The Coronary Heart Disease (CHD) Policy Model is a state-transition computer simulation model, which has been used to obtain forecasts of the public health impact and economic cost of CHD in the U.S. population. The proposed project will adapt the CHD Policy Model to evaluate the cost- effectiveness of cholesterol-lowering strategies in the U.S. population, specifically: 1. To add to the CHD Policy Model the capability to model the consequences of reductions in LDL cholesterol and increases in HDL/LDL ratios in the U.S. population. 2. To use the CHD Policy Model to compare the implications of using alternative epidemiologic studies as the basis for estimating the association between cholesterol levels and CHD risk. 3. To derive cutting points for initiating cholesterol reduction, specific to age, sex, and CHD risk factors, and based on cost-effectiveness criteria. 4. To compare the cost-effectiveness of specific targeted and population- wide strategies for cholesterol reduction. Targeted strategies to be evaluated will include both secondary prevention, and primary prevention targeted according to other CHD risk factors. 5. To incorporate the effects of treatments on quality of life, including both adverse effects of cholesterol-lowering drugs and reductions in CHD morbid events. 6. To perform a cost-effectiveness analysis of cholesterol screening, incorporating costs of screening, effects of measurement error on misclassification of patients, and variations in individual cholesterol levels over time.